Imprecise excision of the P{PTT-GB} element. A portion of the original insertion appears to still be present (this portion contains Avic\GFP sequences but lacks functional w[+] sequences). This lesion is located within both the LamC and ttv transcription units (since LamC is nested within an intron of ttv). However, only LamC function is affected, since the "EX364" chromosome complements ttv00681b and fails to complement LamCEP2199.